1. Field of the Invention
The present invention relates to a hood for connection to the mouth of a steelmaking converter, and more particularly to a hood which incorporates one or more pressure-measuring points.
2. Description of the Prior Art
A conventional method of producing steel in a converter uses a hood adapted to be connected to the mouth of the converter. In this way secondary combustion of inflammable gases released during the steelmaking process can be prevented. The secondary combustion takes place above the converter and in the hood as a result of the entry of surrounding air. In this process therefore, it is very important to be able to measure accurately the gas pressure in the hood. It should be noted that the pressures concerned are of the order of a 1 mm column of water and that the control effected by an exhaust fan connected to the hood has to be based on the pressure measured in the hood.
It is common practice to incorporate several measuring points into the wall of the hood for this purpose. These measuring points consist of pressure meters fitted in water-cooled tubes. The pressure meters are inserted in the water-cooled wall of the hood. The provision of pressure-measuring points increases the complexity of the hood construction and hence increases investment costs. However, one of the main drawbacks of the known construction is that these measuring points often become contaminated by materials originating from the reaction gases. Additionally, in order to achieve reliable pressure measurements it is usually necessary to fit at least three or four measuring points and also to clean those periodically. Special reaming devices have been developed for this purpose. The disadvantages mentioned lead to high maintenance costs, and the pressure measurements produced still leave much to be desired.